I think it tells you a lot about Ardent's personality that, after everything that has happened to him over the past volume or two, his response to this turn of events is: "Yeah! Adventure!" Pure enthusiastic optimisim; that's our Blue!
Meanwhile, Gavia continues to sulk, scowl and... well, basically act like a teenage girl. Which makes her insistence that "We are not children" all the more ironic.
Who's Alice's "acquaintance?" I vote Bubbles. Or another Alice clone.
No AIs left on Earth, remember? I'm thinking that it might be one of Alice's kind or possibly someone with a connected back-story to Alice. It's quite likely that, due to events, any friendship that they may have ever shared has long since been buried in millennia of petty disagreements, inadvertent slights and that, after a few thousand years you could get tired of anyone's face.
[edit]
Wait a minute! There's a
Big Red Button? Since when has there been a
Big Red Button and what exactly does it do so that Alice will know to come running? Proof that she has a radio transceiver in her somewhere?
Big Red Button!